FIG. 1 depicts telecommunications system 100 in accordance with the prior art. Telecommunications system 100 comprises telecommunications network 105, interactive voice response (IVR) system 110, and database system 115, interconnected as shown.
Telecommunications network 105 is a network such as the Public Switched Telephone Network [PSTN], the Internet, and so forth that transports signals between IVR system 110 and other devices, such as telecommunications terminal 106. Telecommunications terminal 106 is a device that is capable of handling voice signals from a user, such as a desktop or notebook computer with a microphone/headset combination, a cellular phone, a hands-free messaging system, and so forth.
IVR system 110 is a data-processing system that enables a user to log in from a remote telecommunications terminal by accepting a combination of voice input and touch-tone keypad selection from the user, and by providing appropriate responses to the user in the form of voice or other media. The user interacts with IVR system 110 to acquire information from or provide information to associated database server 115. The user, having an account on database server 115 or on some other data-processing system associated with system 110, can access one or more resources or services via a telecommunications terminal such as terminal 106 once system 110 grants access to the user.
FIG. 2 depicts a signal flow diagram of signals exchanged between terminal 106 and IVR system 110 in accordance with the prior art. In the signal flow, the user of terminal 106 attempts to access a resource that is associated with database server 115. In response, system 110, which controls the access to server 115, performs authentication on the user by using a first technique in the prior art. Authentication is the process by which a security system, such as one that comprises system 110, verifies that a user is indeed who he or she claims to be. Authentication is a well-understood process in data communications, and many protocols exist in the prior art that provide a level of security through authentication.
Terminal 106 transmits, via signal 201, the user's identity to IVR system 110. System 110 then looks up the corresponding personal identification number (or “PIN”) for the user who is “logging in.”
IVR system 110 transmits, via signal 202, a prompt for the user of terminal 106 to enter his or her PIN.
Terminal 106 transmits, via signal 203, the PIN information that the user enters via the terminal's keypad.
If the PIN transmitted via signal 203 matches the user's PIN on record, IVR system 110 grants the user, via signal 204, access to the requested resource.
The disadvantage in using this first authentication technique is that many telecommunications terminals are hands-free devices that are operated by user voice commands—sometimes exclusively by voice commands. If such a terminal's user speaks a password instead of entering it via a keypad, then eavesdroppers can hear the password, and the security of database server 115 is consequently breached.
Other techniques for authenticating a user exist in the prior art. In a second technique in the prior art, the user speaks the password while ensuring that no one can overhear the spoken password. The disadvantage with the second technique is that it is often unreasonable to rely on the user to ensure that no one can overhear. In a third technique in the prior art, the user utilizes an electronic token device or a list of numbers to respond to an authentication request with a one-time password response. The disadvantage with the third technique is that it is inconvenient for the user to carry around the token device or list, and having to carrying around something is anyway inconsistent with the notion of using a hands-free terminal. In a fourth technique in the prior art, the authenticating system performs speaker verification on the person requesting access. The disadvantage with the fourth technique is two-fold: the high error rate of speaker verification and concerns that an eavesdropper can record and, therefore, impersonate the user's voice make using the speaker verification technique problematic.
Therefore, what is needed is a secure authentication technique that is based on voiced user responses, without some of the disadvantages in the prior art.